Wearable headlamps are frequently used to provide illumination for various sporting and commercial endeavors. As an example, many sporting headlamps are provided with an elastic head band that allows hikers and climbers to wear the headlamps on their head or helmet in order to provide hands-free visibility in low-light conditions. Headlamps of this type are often used, for example, when navigating a trail at night, pitching a tent in darkness, or performing an early morning alpine ascent. These headlamps may also be adapted to provide hands-free illumination in commercial and public safety environments, such as low-light constructions sites or during a fire rescue.
However, wearable headlamps known in the art have a number of drawbacks. In the applications described above, there is often a need to adjust the intensity of the light emitted from the headlamp. A hiker navigating a trail in darkness would require a high-intensity beam of light to see the path in front of him, but would prefer a much lower intensity beam when looking down at a map, which would be nearly blinding if illuminated by a high-intensity beam. Moreover, excessively bright light may cause the user's eyes to over-adjust when viewing an illuminated surface, which can limit subsequent low-light visibility (e.g., when viewing stars through a telescope).
Although existing headlamps include light sources configured to emit light having a manually adjustable luminous intensity, it can be inconvenient for users to repeatedly adjust the luminous intensity of the emitted light manually, particularly during the involved activities described above. Existing headlamps also include limited options for otherwise adjusting the intensity or wavelength of light emitted from the headlamp. Thus, there is an ongoing need in the art for a headlamp capable of adjusting the luminous intensity of its emitted light more conveniently than existing headlamps, and for a headlamp with a greater range of illumination options to suit a wider variety of applications.
Certain headlamps are further adapted such that their light sources can be moved or otherwise adjusted in order to redirect emitted light. For example, climbers may find it useful to direct the emitted light forward and in front of them during an alpine ascent, but may wish to direct the emitted light downward when tying off a rope or engaging a belay device. However, directionally adjustable headlamps in the art are often difficult to redirect or prone to being inadvertently adjusted during use.
In addition to the above, the light sources used in existing headlamps must dissipate the heat that is generated. As an example, certain existing headlamps utilize heat sink devices contained within a housing to dissipate large amounts of heat generated by the headlamp's light source (e.g., an LED). However, dissipating heat generated by a light source via internal heat sinks of this type can cause the housing itself to heat, rendering the headlamp uncomfortable for a user to wear.